Find the derivative (dy/dx) of (cot x)/ (1+cotx)?

1st " - [sec x]^2 / [1 + tan x ] ^2, 2nd 4 [sec x]^2 -[csc x]^2, 3rd; 2x sin x + x^2 cos x, 4th no t in this thus 0 ; 5th : [ - csc t cot t (1-csc t) - ( 1 + csc t ) (csc t cot t) ] / [1 - csc t]^2